Armor sheath stripper for electrical conductors



Dec. l, 1970 J. w. 'rlBBEYr i 3,543,614

- ARMOR SHEATH `STRIPPER Foa ELECTRICALVCoNUcToRs I Filed July 17, 196e70 '(94' a, 6@ .I I/' n if# 74 I I l l I n I l III l II: l ',.44 L t 30I l' FIG 5 I I I .j l 84 f so a4 f/f 'w8 l V f. 'la

INVENTOR JAMES wfrlBBT BY M7 ATTCRNEY United States Patent O W 3,543,614ARMOR SHEATH STRIPPER FOR ELECTRICAL CONDUCTORS James W. Tibbet, Rte. 1,Box 94, Tampman Road, Gold Hill, Oreg. 97525 Filed July 17, 1968, Ser.No. 745,454 Int. Cl. H02g 1/12 U.S. Cl. 81-9.5 10 Claims ABSTRACT OF THEDISCLOSURE Armor sheaths composed of high-pitched, spirally wrapped,metallic wires, commonly called rod, are conventionally provided onaluminum power line conductors at points of conductor support. Linemenare frequently required to relocate sheaths along a conductor.

The invention provides a hot line tool, operable through the familiarshotgun, which can be applied from the side to an unbroken conductor,and similarly removed. The tool includes a two-part nose cone havingteeth on its Working face for digging into, between and beneath thewires of the sheath and, through a to and fro, step by step rotaryaction, unwinding, separating and detaching the wires of the sheath fromthe conductor and from one another without cutting the sheath wires. Theoperation can be performed in a safe, rapid and eicient manner, andwithout damage to the conductor.

'Ihis invention relates to a novel tool for stripping armor sheaths frominstalled and active power line conductors.

In power line conductors there has been a strong trend in recent yearsfrom copper to aluminum. Wherever aluminum is used as the conductormaterial it is the practice to provide an armor sheath three to fourfeet long at each point of conductor support. The sheath is composed ofa bundle of metallic wires, which are tightly twisted about theconductor into steep-pitched spiral form.

The sheath performs a number of useful functions. It constitutes atough, relatively rigid connecting means through which the conductor maybe tied to a supporting insulator, while avoiding direct, abradingcontact between the vulnerable conductor on the one hand and theinsulator and/or tie on the other. It serves as a vibration dampener forthe conductor. In some installations it is so relied on for reinforcingthe conductor at the point of greatest tensile strain as to make aconductor reinforcing core of iron unnecessary.

The twisted wire armor sheath has proved an instrumentality of greatworth, but it has the drawback that up to the present time no practicalmeans has been contrived for economically and conveniently removing thearmor sheath from the conductor. This is an important drawback, becausethe occasions requiring the removal of armor sheaths are numerous.

Frequent line revisions are required by the evergrowing need forexpanded service. Old poles rot away and replacement poles must beerected nearby ybefore, the conductors can be detached from the mountson the old poles. For the new set-up the old armor sheaths are notproperly located. It is impossible to overlap sheaths. The old, and nowdiscarded, sheaths ought not simply to be left in place because theyimpose an unnecessary physical load on the conductors. Most revisionsand repairs are required to be made without interruption of service, sothat whatever service is performed upon the conductors must, if at allpossible, be hot line work.

At the present time there is no satisfactory Way of stripping armorsheaths away. In some instances the old sheaths are left on theconductor, but where overlap 3,543,614 Patented Dec. 1, 1970 lCe wouldbe unavoidable, they must be taken off. A manual tool is commonly usedhaving a bent and sharpened end, and the armor wires on the hotconductor are individually picked at from a distance. The process istedious and awkward, and the conductor is very likely to be damaged.

The primary object of the present invention is to provide a tool wherebywrapped on armor sheaths of the kind referred to can be expeditiously,economically, conveniently and safely removed, and preferably in suchcondition that the wires composing the sheath can be salvaged for reuse.

It is a salient feature that the tool is adapted to be used inconjunction with the familiar shotgun on energized, high voltageconductors; i.e., voltages sufficient, at least, to kill or seriously toinjure, a lineman.

Other objects and advantages will hereinafter appear.

In the drawing forming part of this specification,

FIG. 1 is a View in side elevation, showing a tool illustrative of theinvention and constituting a presently preferred, practical andadvantageous embodiment thereof;

FIG. 2 is a view of the tool partly in rear elevation and partly insectional elevation, showing the tool applied to a conductor, thesection being taken on the line 2 2 of FIG. ,1, looking in the directionof the arrows;

FIG. 3 is a view in front elevation of the two-piece nose cone which isdesigned to engage with and to unwind the armor rods;

FIG. 4 is a fragmentary view in side elevation, similar to FIG. l butmore comprehensive, on a much reduced scale, and somewhat diagrammatic,showing the tool associated with a conductor and with an armor sheathwhich it has started to unwind;

FIG. 5 is a detail view on a larger scale than FIGS. 1 to 3, showing thelower or movable jaw and an adjusting device carried by such jaw foraccommodating the tool to conductors of different diameters; and

FIG. 6 is a view of the structure of FIG. 5 as viewed from the right ofFIG. 5, the scale being the same as that of FIG. 5.

The adjusting device of FIGS. 5 and 6 is shown in FIG. 2, but isintentionally omitted from FIG. 1 in order not to obscure other featuresof FIG. 1.

In FIG. 4 a typical power line installation is shown as regards a singleconductor 10. The conductor is surrounded by a conventional armor sheath12, composed of a bundle of conductive wires or rods 14 which, accordingto convention, are wound into steep-pitched, intertwined, right-handspirals. The wires are shown in the preliminary stage of being unwoundby the novel tool 16. The tool is both slidable to and fro along theconductor 10, and can be turned, in alternation, clockwise andcounterclockwise about the conductor as an axis. The operation will bebetter understood after the tool has been more completely described. Forthe present it may be noted that the tool 16 having been applied to theconductor is moved forward, toward the left from the position in whichit is shown in FIG. 4, to place the left hand or working face of a nosecone 22 in engagement with the right end of the sheath 12. The tool isthen rotated a fraction of a turn clockwise, as viewed from the right inFIG. 4, to partially unwind the wires 14, withdrawn along the conductor10 a short distance, turned counterclockwise idly, and again advanced tostart a further four motion series of steps like the one just described.This is repeated until the portions of the wires 14 to the right of theinsulator 20 are freed. The tool is then removed and applied to the leftof the insulator, the same procedure being followed as before. The toolis then taken away, the sheath is detached from the insulator, and thewires 14 are removed with other hot stick control.

The conductor 10, having been made independent of the pole 24, cross-arm26, and insulator 20, can be mounted through a fresh armor sheath,appropriately located, on a fresh combination of pole, cross-arm andinsulator.

The nose cone 22 consists of upper and lower separable sections 28 and30, which can be snugly fitted together as seen in FIGS. 1, 2 and 3, thelines of separation 32 and 34 being plainly indicated in FIG. 3. Asshown, the apex angle of the truncated cone is ninety degrees, althoughthis angle could be varied over a substantial range. The sections 28 and30, when brought together, form a circular opening at the center capableof accommodating comfortably a conductor 10, of the largest diameter forwhich the particular tool chosen for illustration is designed. It shouldbe noted, however, that, as seen in FIG. 2, the tool is shown associatedwith a conductor of the smallest diameter for which the particular toolis designed. This point will be dealt with in more detail at asubsequent point. Tools of like structure are designed to cover otherconductor size ranges.

The nose cone is provided on its face with a series of evenly spaced,sharp, raised ribs or blades 36. Nine such ribs are shownillustratively, live being on the upper section 28 and four on the lowersection 30. The leading or inner ends of the ribs 36 are made sharp todig into the end of the armor sheath. Each rib is desirably made arcuatein form as shown, and, also as shown, has its leading, inner enddisposed in advance of its trailing, outer end. These details are,however, subject to considerable variation within the scope of theinvention, so long as the nose cone is adapted effectively to spread anduutwist the wires 14. The nose cone at its base or circumference isdesirably scalloped between blades, as shown, a feature which increasessubstantially the effectiveness of the cone in unwinding and separatingthe wires.

The upper section 28 of the nose cone is desirably made unitary with anupper, generally semi-circular carrying jaw 38, as by welding. The lowernose cone section 30 is similarly made unitary with a lower carrying jaw40 which has the cross-sectional form of an inverted T. The jaws 38 and40, when brought together, form an enclosure of restricted but definitesize for the conductor 10, which extends for a considerable distance,say half a foot or so, lengthwise of the conductor 10. They cannot bindthe conductor, but they do serve to guide the tool for to and fro bodilymovement along the conductor and for to and fro rotary movement aboutthe axis of the conductor. The length of the jaws is, to a considerabledegree, a matter of choice. It should be noted, however, that long jawsprevent the possible imposing of highly localized lateral strain on theconductor.

At a point intermediate its ends the upper jaw 38 has atixed to it, asby welding, an upper jaw carrier 42. In the same region the lower jaw 40has affixed to it, as by welding, a lower jaw carrier 44.

The upper jaw carrier 42 has a hollow, downwardly extending, bodyportion 46, desirably elliptical in crosssection, which is formed with alongitudinal slot 48 in one side of its lower end, and includes at thesame side of its upper end an integral projection 50 on which the jaw 38is carried.

The lower jaw carrier 44 has an elliptical body portion 52 which fitsslidably within the body 46 of the upper carrier 42, and is operablelengthwise thereof. The body 52 has integral with it a projection 54 towhich the lower jaw 40 is affixed. The projection 54 extends through theslot 48 and is held against rotation by the walls of the slot. Theprojection 54 is generally wider than the slot 48, but the projection isformed with channels 56 in its opposite sides for slidably receiving theslot walls.

A threaded stem 58, having a ring 60 at its lower end, is provided aspart of the upper jaw unit for manipulating the tool as a whole and foradjusting the lower jaw unit, including the carrier 44, relative to theupper carrier 42. The stem 58 has a full diameter portion, the upper endof which is continuously threaded as shown at 62, and is threadedthrough the body 52 of the lower carrier. The stem 58 is freelyrotatable but it is anchored at its upper end against axial movementrelative to the upper carrier 42. For this purpose, the stem 58 isprovided with an extreme upper end portion 64 of reduced diameter whichpasses upward, with substantial clearance, through an opening of thecarrier 42. A bushing 66 fills the space between the circumference ofthe carrier opening and the stem 58. A washer 68 rests on the shoulderof the stern 58 formed at the junction of the full diameter and thereduced diameter portions of the stem, bearing upward against the upperend of the elliptical chamber formed in the upper carrier body. Theprotruding, reduced upper end 64 of the stem 58 is threaded. A nut 69 isscrewed onto the stem 58 far enough to retain the parts, with freedomfor rotation, in the relative positions in which they are shown in FIG.2, and is so retained by a pin 70. The pin 70 is driven through the nut68 and through the reduced upper end 64 of the stem 58. The lower end ofthe upper carrier body 46 is closed by a bushing 72, the bushing beingxed in place by a set screw 73 and forming a bearing for the stem 58.The bushing is desirably made long and narrow so that it can be receivedin one of the crossing slots of the shotgun.

It will be apparent, assuming a right hand thread 62, that a clockwiserotation of the stem 68 carries the lower jaw 40 away from and clear ofthe upper jaw 38, at the same time separating the lower section 30` ofthe nose cone 22 from the upper section 28 thereof. This makes itpossible, through the use of a shotgun, to hang the tool on theconductor 10 with the hollow upper jaw 38 supporting the tool. The lowerjaw can then be closed on the upper, by manipulating the shotgun torotate the stem 58, the sections of the nose cone being brought backtogether by the same action. The tool can now be manipulated by theshotgun to give it the four motion feed already described, for strippingthe sheath progressively from the conductor.

The point cannot be over-emphasized that this tool is adapted andintended for hot line work in stripping conductive wire sheaths fromintermediate portions of conductors, and that every manipulative stepdescribed can be executed with safety and finesse through theconventional, insulating shotgun.

It is not necessary to provide a distinct tool for every differentconductor size. A size adapting device is shown in FIG. 2 and isillustrated on an enlarged scale in FIGS. 5 and 6. the web or T body 74of the lower jaw 40 is punched outward to provide openings 76, a portionof the outwardly displaced metal being retained and utilized to provideperforated ears 78. Midway between the ears 78 a threaded stud 80,having a steep-pitched thread, projects outward from the outer face ofweb 74. A circular knurled nut 82 is threaded on the stud 80 and bearsoutward against the middle of a bowed spring 84. The spring 84 passesthrough the openings of ears 78, and has its ends received freely in theopenings 76 of the web 74. Rotation of the nut to force the center ofthe spring outward forces the ends of the spring inward as shown in FIG.5, beyond the inner face of the web 74. The ends of the inner faces ofthe spring are smoothed out and made concave in order to avoid damage tothe conductor 10. As seen in FIG. 2, the inward projection of the springends narrows the wire receiving space between the jaws, adapting thetool for use on conductors of reduced diameters. Suitable means areprovided for enabling the user to preset the device for the knowndiameter of the conductor. The presetting is important because this ishot line work.

The outer face of the spring l84 is provided at its middle with an indexmark 88, and appropriate index marks designated, respectively, 4, 2 and1/0 are provided on the outer face of nut 82. Bumps 90, 92 and 94 on theface of the nut 82 cooperate with a dimple 96 on the inner face of thespring 84 for detaining the nut yieldingly in positions corresponding tothe several conductor diameters indicated on the face of the nut.

The stud has an outer end portion 86 of reduced diameter which passesfreely through a small hole formed through the spring 84 for limitinglengthwise movement of the spring relative to the stud.

I have described what I believe to be the best embodiments of myinvention. I do not wish, however, to be confined to the embodimentsshown, but what I desire to cover by Letters Patent is set forth in theappended claims.

I claim:

1. A tool adapted for removing from an intermediate length of acontinuous, energized power line conductor, an armor sheath composed ofa bundle of steep-pitched, spirally wrapped metallic wires, comprising,in combination,

(a) upper and lower jaw units including, respectively, opposed,elongated upper and lower jaws, which jaws are adapted when broughttogether, to define a conductor confining but nonclamping enclosure, andinteriitting, relatively movable jaw carrying members upon which theupper and lower jaws are, respectively, ixedly carried,

(b) cooperative operating means forming parts of the respective unitsand constructed and arranged for relative operation to bring the jawstogether to define the conductor defining enclosure and to retain themso, or to separate the jaws at will so that the tool can be laterallyapplied to, and removed from, the conductor, and

(c) a two-piece nose cone having a central conductor receiving openingand having its two complementary sections made unitary, respectively,with the upper and lower jaws, so that the nose cone can be opened andclosed along with the jaws, the nose cone pieces including blades orribs on their working faces, which converge at the smaller end of thecone for engagement with the ends of the sheath wires, the cone bladesbeing adapted under the guidance of the conductor to the gauge into,between and beneath the sheath wire ends and to unwind, expand andseparate the intact sheath wires from the conductor and from one anotherthrough rotary motion of the tool about the conductor.

2. A tool as set forth in claim 1 in which the nose cone is scallopedbetween the blades at its outer or larger end.

3. A tool as set forth in claim 1 in which the nose cone blades arecurved to present convex leading surfaces with the leading inner ends ofthe blades in advance of the trailing outer ends of the blades.

4. A tool as set forth in claim 1 in which the means for moving theupper and lower jaws toward and from one another comprises a threadedbore through the lower jaw carrier, and a rotatable screw threadedthrough said bore and fixed against bodily movement in, and relative to,the upper jaw carrier.

5. A tool as set forth in claim 4 in which the rotatable screw protrudesdownward beyond both said jaw carriers and terminates in. a ring adaptedto be received in, and to be interlocked with, a conventional shotgun.

6. A tool as set forth in claim 1 in which an adjusting device iscarried upon the lower jaw and adapted to project inward more or lessbeyond said jaw for narrowing the conductor confining space between theclosed jaws by different predetermined amounts as required by the knowndiameter of the conductor upon which the tool is to be used.

7. A tool as set forth in claim 6 in which the adjusting devicecomprises outwardly displaced perforated ears on the lower jaw, a bowedspring mounted on the outer side of the lower jaw with its ends passedthrough said ears and located in positions to pass freely throughopenings formed in said jaw, a threaded stud projecting outward from amid-portion of the lower jaw, and an adjusting nut threaded on said studand bearing outward against the inner face of the spring, theconstruction and arrangement being such that the spring ends are forcedinward by outward adjustment of the nut.

8. A tool as set forth in claim 7 in which the bowed spring has acentral opening formed through it, and the stud has a reduced outer endwhich is received in said hole for retaining the spring in the desired,operative association with the lower jaw.

9. A tool as set forth in claim 7 in which the inner face of the springand the outer face of the nut are formed with interfitting parts foryieldingly detaining the nut in predetermined positions, and suitableindicia are provided on the spring and on the screw head for indicatingthe conductor gauge or diameter for which each such position isappropriate.

10. A tool as set forth in claim 9 in which the interfitting parts onthe spring and the nut consist of a single recess 0r dimple on the innerface of the spring and a plurality of complementary bumps or projectionson the outer face of the nut.

References Cited UNITED STATES PATENTS TRAVIS S. MCGEHEE, PrimaryExaminer UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentNO- 3,543L6l4 Dated December I7 1G70 Inventor(s) James W., Tibbet It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 5 line 37 "the gauge" should read gouge Signed and sealed this13th day of April 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, Attesting OfficerCommissioner of Pate FORM PO-OSO (1D-69) .-.fum..

